In the riveting of assemblies for connecting at least two parts together, it is common practice to provide visual inspection after the rivets have been applied by an operator with a hand-held, power-operated, rivet setting tool to assure that the predetermined number of rivets has been applied and such rivets have been properly installed. Such may be used on air bag door assemblies in an automotive instrument panel. Before the instrument panel with the air bag door assembly is allowed to be removed for subsequent assembly with the remainder of the air bag system in a vehicle, the operator visually ensures that the predetermined number of rivets have been properly installed. This is a significant time consuming and tedious task, and the operator can be distracted and err in carrying out such important assignment. There is limited ability to control the quality of such riveting process by an operator.
Where the rivets used are of the blind type having a break-away, rivet-setting mandrel, it has been proposed as disclosed in U.S. Pat. No. 5,125,151, issued Jun. 30, 1992 in the name of Smart, to count the number of rivets that are set in a work cycle on an assembly by sensing the spent mandrels with a proximity switch as they are carried away from the riveting tool by vacuum collection tube. When the mandrel count at the end of the work cycle is less than the prescribed number of rivets to be applied, a warning light is activated and the system is disabled from starting another work cycle until the required number of spent mandrels has been counted.
However, this patent does not preclude the possibility of a riveted assembly with less than the required number of rivets from being removed from the riveting workstation and sent on for its intended use, nor the improper installation or crushing of the rivets.